The present invention relates to a disposable assembly for separating blood or the washing of a blood component by centrifugation, comprising a circular centrifuge chamber made of a rigid plastic, comprising, at an end lying on its axis of rotation, an element shaped in order to mesh with a drive member of a centrifuge machine and, at an opposite end, a member for interaction of said chamber with the outside made of a rigid plastic, connected to said centrifuge chamber by a rotary joint and passed through by a tube to supply this chamber and by at least one outlet tube for draining one of the separate constituents, a support made of a rigid plastic in which a network of channels is formed in order to connect said tubes respectively to a supply reservoir for the blood to be separated and to respective reception reservoirs for the separated constituents, elements for laterally closing this network of channels in a sealed manner and means for circulating the fluids through this network of channels from the supply reservoir to the reception reservoirs.
The single-use centrifugation assemblies used to separate blood components from whole blood comprise two main parts: a movable part corresponding to the centrifuge chamber and a fixed part comprising storage pouches for blood components, flexible tubing, and all the parts intended to be connected to the machine controlling the process of separating blood components, such as the interfaces with the pressure sensors, the pumps, the air detectors, the clamps in particular. The centrifuge chamber may be made of a rigid plastic.
Generally speaking, the term “rigid” used in the description and the claims to qualify the plastic materials used relates to materials that are neither flexible, nor soft, nor pliant, i.e. to plastics capable of preserving their initial shape in the conditions of use for which they have been designed.
In the centrifuge assemblies mentioned above, the connection between the movable part and the fixed part is always made using flexible tubing which considerably inhibits the mounting of the centrifuge assembly on the machine, appreciably increasing the working time of the operator and the risk of defective mounting.
It has already been proposed to integrate various elements of a blood separation device on a rigid support, without all the same eliminating the flexible tubes between the centrifuge chamber and the fixed part of the assembly.
WO 8,402,473 shows a molded structure for a plasma fractionation machine comprising fluid flow channels and a membrane filter for separating the plasma from the whole blood. It is not therefore concerned with separation by centrifugation.
US 2004/0245189 relates to a single-use separation assembly comprising a cassette comprising a frame made of injection-molded plastic that supports tubing ultrasonically welded to the frame and a continuous flow centrifuge chamber. The centrifuge chamber is connected in a removable manner to the frame of the cassette in order to be able to be inserted easily into a rotor of the centrifuge during installation of the cassette, so that the centrifuge chamber is uncoupled from the frame of the cassette when the door of the centrifuge apparatus is closed. The connection between the fixed connecting tubes for connecting the centrifuge chamber to the outside and the tubes respectively joined to the centrifuge chamber is produced using a rotating cylindrical part having, on its outer face, a series of annular channels, a fixed part having a face adjacent to the external face of the rotating cylindrical part is passed through by tubes opening onto this adjacent face, at respective radial distances from the axis of the rotating cylindrical part chosen to bring each tube to interact with an annular channel of the rotating part. The seal between the rotating cylindrical part and the fixed part is ensured by an elastic pressure of the adjacent faces of these two parts. Given the rotation speed of the centrifuge chamber, such a solution poses serious heating problems which is capable of damaging the processed blood passing into the annular channels formed on the rotating cylindrical part, and in the tubes of the fixed part pressed elastically against the rotating part, rotating at several thousand rotations/minute to guarantee the seal in the fluid flow.